Field of the Disclosure
The present disclosure relates generally to processing devices and, more particularly, to modifying a temperature value that is used to estimate leakage currents in processing devices.
Description of the Related Art
Processing systems such as a system-on-a-chip (SOC) incorporate multiple components of a processing device onto a single substrate. For example, an SOC such as an accelerated processing unit (APU) may use a single substrate to support and interconnect processing devices such as central processing units (CPUs) and graphics processing units (GPUs), as well as a physical layer interface to external memory and additional logic for controlling operation of the components. The CPUs or GPUs can read instructions or data from the external memory via the physical layer interface, perform operations using the instructions or data, and then write the results back into external memory via the physical layer interface. The total power consumption of an SOC includes the power consumed by operation of the components of the SOC and leakage currents that consume power but are not used to operate the components of the SOC. Leakage currents may consume a significant portion of the total power consumed by the processing device.
Leakage currents are strongly temperature dependent and increase sharply with increasing temperature through the temperature range typically found in processing devices. Consequently, the dynamic power available for operation of the SOC (i.e., the difference between the thermal design power (TDP), and the power consumed by the leakage current) also depends on temperature. In order to set the operating frequencies or operating voltages (e.g., the operating points) of the components of the SOC, the temperature at one or more locations in the SOC is measured or calculated based on the power consumption at the one or more location. The leakage current is then estimated based on the temperatures and used to estimate the available dynamic power for one or more components of the SOC. The one or more operating point of the components can then be set so that the SOC or components draw approximately the available dynamic power.